The present invention relates to the sterilization of thermosensitive instruments and, more specifically, to an apparatus and a method for sterilizing thermosensitive instruments while exposing the instruments to substantially room temperatures during the sterilization process.
Current methods for sterilizing medical instruments include using steam autoclaves, using ethylene oxide, or using irradiation. While these methods are effective for sterilizing instruments, none of these methods are suitable for performing instrument sterilization at a patient side location while exposing the instrument to substantially room temperatures during the sterilization process.
Steam autoclaves operate at temperatures ranging between two hundred-forty degrees Fahrenheit and two hundred seventy-five degrees Fahrenheit for extended periods of time. The high temperatures used by steam autoclaves have been known to damage thermosensitive instruments, such as the turbines of a dental handpiece, and tend to reduce the useful life of the thermosensitive instruments that are sterilized using steam autoclaves. This results in the associated medical instruments requiring more frequent and expensive refurbishing.
Ethylene oxide is a carcinogenic, flammable, and highly toxic substance. Expensive ventilation systems are required before the discharge resulting from the ethylene oxide sterilization process is released to the atmosphere. Thus, the use of ethylene oxide raises safety issues with regard to the sterilization of instruments at a patient-side location. Problematic environmental issues are also associated with the use of ethylene oxide.
The use of irradiation for sterilization is not a practical solution for normal patient-side applications. Irradiation sterilization requires large and expensive installations and protective measures which makes irradiation sterilization unsuitable for use at a patient-side location.
Currently, the pre-cleaning of soiled medical instruments prior to the exposure of the instrument to the actual sterilizing heat, chemicals, or radiation depends on manual cleaning which is performed by medical personnel. The reliance on medical personnel for the manual cleaning of instruments increases the chance of inadequate cleaning due to human error or due to the omission of pre-cleaning all together.
What is needed, but so far not provided in the sterilizing art is an apparatus and method for sterilizing thermosensitive instruments at substantially room temperature, using automated processes, which does not require a manual pre-cleaning, in a manner that is convenient and safe for use at a patient-side location during the treatment of the patient.
Briefly stated, the present invention is directed to an apparatus for sterilizing an instrument having an exterior surface at substantially room temperature. The apparatus includes a chamber having an interior compartment for receiving and housing the instrument. The interior compartment is maintained at a predetermined compartment temperature while the instrument is being sterilized. The chamber is releasably engagable with a portion of the instrument to support the instrument within the interior compartment. A fluid injection mechanism is in fluid communication with the chamber for supplying fluid to the chamber and for maintaining the fluid at a predetermined fluid temperature while the instrument is being sterilized. The chamber includes at least one fluid outlet for directing a flow of fluid onto the exterior surface of the instrument. The chamber further includes at least another fluid outlet to direct the flow of fluid onto the portion of the instrument engaged by the chamber.
The present invention is alternatively directed to a method of sterilizing an instrument having an exterior surface at substantially room temperature. The method includes the steps of: securing the instrument inside of a chamber by removably engaging a portion of the instrument to the chamber; removing bio-burden from the instrument by exposing the instrument to at least one bio-burden removing fluid while maintaining the chamber and the at least one bio-burden removing fluid at about a first predetermined temperature; and sterilizing the instrument, including the portion of the instrument engaged by the chamber, by exposing the instrument to at least one sterilizing fluid while maintaining the chamber and the at least one sterilizing fluid at about a second predetermined temperature.
Alternatively, the present invention is directed to a coupler for supporting an instrument inside of a sterilizing apparatus. The coupler includes a porous body having a first end and a second end. The porous body receivably engages a portion of the instrument on the second end. A non-porous body substantially surrounds the porous body causing a flow of a fluid that enters the first end to flow toward the second end of the porous body and into contact with the portion of the instrument engaged by the coupler to expose the portion of the instrument to the fluid.